Progress in a society can be measured by steady improvement in health outcomes. The United States has made progress in some health areas over the years. Other health issues, however, have proven more challenging and some have even worsened considerably. Health outcomes differ widely across states, and the likelihood of living a healthy life largely depends on where you live, according to the latest report from the United Health Foundation.

To provide a more complete picture of where the country is succeeding and where it is failing, the United Health Foundation’s 2016 America’s Health Rankings report examined both determinants and health outcomes. The UHF included such factors as healthy behaviors, quality of health care, health policy, the incidence of diseases, and preventable deaths across the nation. Each of these areas varies considerably between states. This year, Hawaii is once again the healthiest, while Mississippi is the least healthy state in the nation.

While the effects of the opioid epidemic are felt in all states, Pennsylvania feels it more than most. There are about 20 drug deaths in the state for every 100,000 residents, far more than the national rate of 14 drug deaths per 100,000 Americans. Other negative health measures in the state include a higher than average smoking rate and a slightly smaller share of adults who are physically active.

While certain unhealthy behaviors contribute to negative health outcomes in the Keystone State, environmental circumstances also partially explain the state’s relatively low ranking. Due in large part to energy production in the state, Pennsylvania has the second worst air pollution in the country after only California.

Across the nation, due to policy and awareness, the smoking rate fell from 29.5% in 1990 to 17.5% last year, and immunization rates for children and adolescents have increased. However, obesity and drug-related fatalities have risen dramatically. Close to 30% of the U.S. adult population is obese, up considerably from 1990 when just 11.6% of adults were obese. Also, there were approximately 47,000 drug overdose deaths last year, or 14 for every 100,000 people, up from 8.5 per 100,000 five years ago.

In an interview with 24/7 Wall St., Dr. Reed Tuckson, external clinical advisor to the UHF, said that a variety of complex factors can explain poor health and the resulting untimely deaths in a given state. Likewise, states typically do well in some health measures and poorly in others. In general, however, “States that are socioeconomically better off do better in the rankings than states that are poor,” Tuckson said.

Of the 25 states on the lower end of the UHF ranking, 18 have poverty rates that exceed the national rate of 14.7%. This is the case in only four of the nation’s 25 healthier states.

Few metrics are more closely-tied to health than education. In 16 of the 25 states on the higher end of the UHF ranking, college attainment rates exceed the national rate of 30.6%. This is the case in only three of the nation’s 25 less-healthy states.

People do not necessarily learn healthy habits at college, but a bachelor’s degree helps provide a greater sense of control over one’s life as Tuckson noted. Because individuals with college degrees tend to earn higher incomes, they also tend to live in wealthier communities. “People who are living in higher socioeconomic environments have more resources available to support them in their personal choices,” Tuckson said.

While health status can potentially be predicted by socioeconomic factors, health is also largely determined by individual behavior. Residents of the nation’s healthiest states are much more likely to report healthy behaviors than residents living in the least healthy states. For example, the percentage of adults who do not take time to exercise outside of work is higher than the national percentage of 26.2% in just six of the 25 states at the top of the health ranking. Meanwhile, physical inactivity is relatively more common in 17 of the 25 less-healthy states.

Tuckson added that while it is by no means easy to overcome social and economic disadvantages, “These are decisions people are making about their lives, these are things that are within the control of the individual.”

By prioritizing public health, elected and other public officials can also make a major difference in the health of a state’s population. Governments are responsible for mobilizing a state’s assets, and poor fiscal management can result in budget cuts to health services. Whether residents of states have the benefit of high health insurance coverage or a good immunization record is largely the consequence of policy decisions and community organizations.

Based on data provided by United Health Foundation’s America’s Health Rankings, 24/7 Wall St. reviewed all 50 states based on their overall scores. The UHF based its ranking on a number of measures that fall into two separate categories: health determinants and health outcomes. Determinants were further divided into behaviors, such as smoking and drinking; community and environmental factors, such as children living in poverty; policy factors, such as public health funding and immunization rates; and clinical care factors, such as the availability of doctors and dentists. Outcomes included rates of death from cancer and cardiovascular diseases, the incidence of diabetes and infectious diseases, as well as infant mortality rates.